Debt Consolidation Calculator

Think of debt consolidation as replacing several lanes of traffic with a single highway. Each lane — your credit card, personal loan, or store card — moves at its own speed (interest rate) and has its own toll (monthly payment). Merging everything into one lane at a single negotiated rate can cut your total toll bill, as long as the new highway charges less per mile than the old roads averaged together.

The core of this calculation is comparing your new consolidated payment against what you are currently paying across all debts. Your current payments are simply added up. The new consolidated payment is computed using the standard annuity formula, which answers the question: if I borrow a fixed amount today at a fixed monthly rate and repay in equal installments, what is each installment? The formula accounts for the fact that early payments are mostly interest while later payments are mostly principal — the math handles this balance automatically.

The weighted average rate is the diagnostic number. If your consolidation offer beats it, interest savings are built into the math. If it does not, the monthly savings you see are coming from the term extension alone — and you should decide whether a lower payment now is worth more total interest later.

This calculator is most useful when you have received a specific consolidation loan offer with a confirmed rate and term, and you want to know immediately whether the math works in your favor. It is also useful as a target-setting tool: run it at several hypothetical rates to find the ceiling rate at which consolidation breaks even against your current payments — then you know exactly what to negotiate for.

The calculator is less appropriate when your debts include a mix of secured and unsecured obligations. Combining a car loan with credit card debt, for instance, involves collateral considerations and lender restrictions that change the risk profile in ways the interest math alone does not capture. Similarly, if any of your existing debts have promotional rates expiring soon, those expiration dates matter more than the current rate shown on your statement.

Do not use this calculator as a substitute for evaluating origination fees and prepayment penalties on your current debts. A consolidation loan with a steep origination fee can erase months of monthly savings in a single upfront cost. The tool assumes no fees — flag any cost structure in your offer before treating the savings figure as final.

Ignoring the term extension effect. People see a lower monthly payment and assume they are saving money, but if the new term is much longer than the time remaining on current debts, total interest can rise even as each payment falls. The monthly savings figure is real — but so is the extra time you spend in debt. Always multiply payment by months remaining on each path before concluding consolidation wins outright.

Entering a rate that is not yet confirmed. Prequalification rates can differ from the rate you actually receive at signing, sometimes by several percentage points depending on your credit profile at the time of application. Running this calculator on a marketing-advertised rate rather than a locked offer will overstate your savings. Use a confirmed offer letter rate for decision-making.

Omitting existing minimum payments accurately. If you normally pay more than the minimum on a high-rate card, entering only the minimum understates your current monthly total and makes consolidation look more attractive than it is. Enter what you actually pay each month, not the floor set by your lender, to get an honest savings comparison.

The annuity payment formula is: P = [r × PV] ÷ [1 − (1 + r)⁻ⁿ], where P is the monthly payment, r is the monthly interest rate, PV is the loan principal, and n is the total number of payments. The monthly rate r is your annual consolidation rate divided by 100 to convert from percentage to decimal, then divided again by 12 to get the monthly figure.

For the example inputs — a total balance of $10,000 at 8.5% over 60 months — you divide 8.5 by 100 to get the decimal annual rate, divide that by 12 for the monthly rate, then apply the formula. The result is a new monthly payment of $205. The weighted average rate formula multiplies each debt balance by its own rate, sums those products, and divides by the total balance: for the example that produces 18.1%.

When the consolidation rate is zero, the formula simplifies to total balance divided by number of months — no interest accumulates, so each payment is purely principal. This is the math behind a 0% balance transfer offer: the $10,000 in the example, divided evenly, gives the flat payment shown in the zero-rate worked example. Any non-zero rate raises that baseline payment by the cost of interest compounded monthly.

The annuity formula assumes a perfectly fixed rate and perfectly consistent monthly payments with no missed payments, no rate resets, and no balance changes from new spending. In practice, credit card balances often drift upward after consolidation because the paid-off cards remain open — a behavior pattern that turns a one-time savings calculation into a growing total debt problem. The formula also assumes the consolidation loan funds on the same day all existing debts are paid off, with no gap during which interest accrues on both simultaneously. These edge cases do not break the math, but they do mean the savings you calculate here are a ceiling, not a guarantee.